Mach3 Lathe Threading Struggles

[m_c]

I'm not sure on the reliability of the threading diagnostics page.
If you open the diagnostics page with all the LEDs, does the one for the index go on/off as you manually move the spindle slot through the sensor?

It does sound like you've got a sensor problem. How big is the slot you're detecting?
Can you run the spindle any slower than 200rpm?

If it works at really slow speeds, it could be as simple as needing the slot enlarged.

[mondrota]

Yes, I can run it slower than 200 rpm. And yes, the index led flashes as I move the spindle by hand. I used to use a slotted disc with a proximity sensor, now I'm using a magnet on the shaft with a hall sensor. The pulse is nice and long, the rpm readout is stable even on max speed (about 1800 rpm).
Thanks

[mondrota]

Okay, it's been a while, and this project was put to a side but now I'm back at it. I bought a cheap USB motion controller from eBay
https://rover.ebay.com/rover/0/0/0?m...2F163110531211
I plugged it in to my laptop for testing, connected some relays and they work okay, however I don't get any rpm readout! The index light comes on in the diagnostic screen but no matter what I do, the sTrue stays at 0 🤔
Is the controller supposed to tell mach3 what the rpm is?
Did I go wrong by going cheap?
Help!

[battwell]

you need a controller that will support threading in the controller. this cannot be done in software.
the index signal must be interupt driven- so its very fast.
software will always lag so you will never get the same start point for threading.
you also require spindle encoder - which can be 2 sensors 60 degrees apart
threading- and cheap- are never going to work

[mondrota]

Thanks for your reply. Will pokeys 57 be suitable for threading?
Thanks

[battwell]

i think they are supposed to work. but ive never tried one.
have a look through the mach3 forum or contact pokeys to fully confirm.

[magicniner]

I bought a cheap USB motion controller from eBay

Hmm, not narrowing the angle there! ;-)

[m_c]

From the top of head in no particular order, the following support turn/single point threading-
Pokeys
PMDX
KFlop
CS-Labs (although I think you may need the higher end controller with an MPG module, and not the cheaper controller)
Centroid


IIRC Pokeys (and possibly PMDX) will work with a basic single/multislot sensor, whereas the rest require a proper quadrature output encoder.

[magicniner]

Does anyone do a good Stand Alone Controller for lathes?

[m_c]

Does anyone do a good Stand Alone Controller for lathes?

When I was looking at the Chinese standalone controllers, I'm sure some were available in turn versions.